A customized airborne optical remote sensing system for polar environments

Kurzfassung

The DLR Institute of Optical Sensor Systems has developed a Modular Aerial Camera System specifically designed for extreme environmental conditions (MACS-POLAR). It is integrated on the AWI Polar-5 research aircraft for permafrost campaigns in Alaska and Canada in summer 2018. MACS is a modular family of project-customized aerial camera systems adapted to specific scientific and operational requirements. Based on the MACS-Himalaya, a system designed for the extreme radiometry and geometry of high mountain ranges, the design of the MACS-POLAR has maintained its robustness (low temperature, low pressure). It comprises a High Dynamic Range (HDR)-Mode for extreme contrast (ice, snow, dark rocks) and a high frame rate for fast velocities and low flight paths, still maintaining sufficient image overlap for 3D-reconstruction. The optical design consists of two overlapping tilted RGB camera heads and a nadir looking near-infrared (IR) camera (ground sampling distance RGB: 9 cm; IR: 15 cm @ 1000 m above ground). The sensor head can be separated from the processing unit to enable installation in small compartments (Fig. 1). In the system small and lightweight industrial grade camera heads are used. Direct georeferencing, real-time processing of image mosaics and multitemporal monitoring without the need of ground control points is possible due to the use of its GNSS (Global Navigation Satellite System) and INS (Inertial Navigation System) units. The operation of the system is highly automated, a remote real-time mission control and access to the images during data acquisition is given to the operator if needed. Products such as dense point clouds, Digital Surface Models and true orthomosaics will be used for scientific analysis of permafrost regions. Near real-time mosaics can be used during the campaign for quality control and planning of ground campaigns.